src/pools/selection-strategies/selection-strategies-types.ts

   1 /**
   2  * Enumeration of worker choice strategies.
   3  */
   4 export const WorkerChoiceStrategies = Object.freeze({
   5   /**
   6    * Round robin worker selection strategy.
   7    */
   8   ROUND_ROBIN: 'ROUND_ROBIN',
   9   /**
  10    * Least used worker selection strategy.
  11    */
  12   LEAST_USED: 'LEAST_USED',
  13   /**
  14    * Least busy worker selection strategy.
  15    */
  16   LEAST_BUSY: 'LEAST_BUSY',
  17   /**
  18    * Least ELU worker selection strategy.
  19    *
  20    * @experimental
  21    */
  22   LEAST_ELU: 'LEAST_ELU',
  23   /**
  24    * Fair share worker selection strategy.
  25    */
  26   FAIR_SHARE: 'FAIR_SHARE',
  27   /**
  28    * Weighted round robin worker selection strategy.
  29    */
  30   WEIGHTED_ROUND_ROBIN: 'WEIGHTED_ROUND_ROBIN',
  31   /**
  32    * Interleaved weighted round robin worker selection strategy.
  33    *
  34    * @experimental
  35    */
  36   INTERLEAVED_WEIGHTED_ROUND_ROBIN: 'INTERLEAVED_WEIGHTED_ROUND_ROBIN'
  37 } as const)
  38
  39 /**
  40  * Worker choice strategy.
  41  */
  42 export type WorkerChoiceStrategy = keyof typeof WorkerChoiceStrategies
  43
  44 /**
  45  * Enumeration of measurements.
  46  */
  47 export const Measurements = Object.freeze({
  48   runTime: 'runTime',
  49   waitTime: 'waitTime',
  50   elu: 'elu'
  51 } as const)
  52
  53 /**
  54  * Measurement.
  55  */
  56 export type Measurement = keyof typeof Measurements
  57
  58 /**
  59  * Measurement options.
  60  */
  61 export interface MeasurementOptions {
  62   /**
  63    * Set measurement median.
  64    */
  65   readonly median: boolean
  66 }
  67
  68 /**
  69  * Worker choice strategy options.
  70  */
  71 export interface WorkerChoiceStrategyOptions {
  72   /**
  73    * Measurement to use for worker choice strategy.
  74    */
  75   readonly measurement?: Measurement
  76   /**
  77    * Runtime options.
  78    *
  79    * @defaultValue \{ median: false \}
  80    */
  81   readonly runTime?: MeasurementOptions
  82   /**
  83    * Wait time options.
  84    *
  85    * @defaultValue \{ median: false \}
  86    */
  87   readonly waitTime?: MeasurementOptions
  88   /**
  89    * Event loop utilization options.
  90    *
  91    * @defaultValue \{ median: false \}
  92    */
  93   readonly elu?: MeasurementOptions
  94   /**
  95    * Worker weights to use for weighted round robin worker selection strategy.
  96    * Weight is the tasks maximum average or median runtime in milliseconds.
  97    *
  98    * @defaultValue Computed worker weights automatically given the CPU performance.
  99    */
 100   readonly weights?: Record<number, number>
 101 }
 102
 103 /**
 104  * Measurement statistics requirements.
 105  *
 106  * @internal
 107  */
 108 export interface MeasurementStatisticsRequirements {
 109   /**
 110    * Requires measurement aggregate.
 111    */
 112   aggregate: boolean
 113   /**
 114    * Requires measurement average.
 115    */
 116   average: boolean
 117   /**
 118    * Requires measurement median.
 119    */
 120   median: boolean
 121 }
 122
 123 /**
 124  * Pool worker node worker usage statistics requirements.
 125  *
 126  * @internal
 127  */
 128 export interface TaskStatisticsRequirements {
 129   /**
 130    * Tasks runtime requirements.
 131    */
 132   readonly runTime: MeasurementStatisticsRequirements
 133   /**
 134    * Tasks wait time requirements.
 135    */
 136   readonly waitTime: MeasurementStatisticsRequirements
 137   /**
 138    * Tasks event loop utilization requirements.
 139    */
 140   readonly elu: MeasurementStatisticsRequirements
 141 }
 142
 143 /**
 144  * Strategy policy.
 145  *
 146  * @internal
 147  */
 148 export interface StrategyPolicy {
 149   /**
 150    * Expects direct usage of the newly created dynamic worker.
 151    */
 152   readonly useDynamicWorker: boolean
 153 }
 154
 155 /**
 156  * Worker choice strategy interface.
 157  *
 158  * @internal
 159  */
 160 export interface IWorkerChoiceStrategy {
 161   /**
 162    * Strategy policy.
 163    */
 164   readonly strategyPolicy: StrategyPolicy
 165   /**
 166    * Tasks statistics requirements.
 167    */
 168   readonly taskStatisticsRequirements: TaskStatisticsRequirements
 169   /**
 170    * Resets strategy internals.
 171    *
 172    * @returns `true` if the reset is successful, `false` otherwise.
 173    */
 174   readonly reset: () => boolean
 175   /**
 176    * Updates the worker node key strategy internals.
 177    *
 178    * @returns `true` if the update is successful, `false` otherwise.
 179    */
 180   readonly update: (workerNodeKey: number) => boolean
 181   /**
 182    * Chooses a worker node in the pool and returns its key.
 183    *
 184    * @returns The worker node key.
 185    */
 186   readonly choose: () => number
 187   /**
 188    * Removes the worker node key from strategy internals.
 189    *
 190    * @param workerNodeKey - The worker node key.
 191    * @returns `true` if the worker node key is removed, `false` otherwise.
 192    */
 193   readonly remove: (workerNodeKey: number) => boolean
 194   /**
 195    * Sets the worker choice strategy options.
 196    *
 197    * @param opts - The worker choice strategy options.
 198    */
 199   readonly setOptions: (opts: WorkerChoiceStrategyOptions) => void
 200 }